package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private IUserService userService;

    /**
     *关注或者取关
     * @param followUserId,isFollow
     * @return
     */
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        // 1.获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key = "follows:" + userId;
        // 1.判断到底是关注还是取关
        if (isFollow) {
            // 2.关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if (isSuccess) {
                // 把关注用户的id，放入redis的set集合 sadd userId followerUserId
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        } else {
            // 3.取关，删除 delete from tb_follow where user_id = ? and follow_user_id = ?
            boolean isSuccess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));
            if (isSuccess) {
                // 把关注用户的id从Redis集合中移除
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }
    /**
     *判断是否关注指定用户的接口
     * @param followUserId
     * @return
     */
    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        //1.查询是否关注
        Integer count = query().eq("user_id",
                userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count>0);
    }
    /**
     *找共同关注
     * @param id
     * @return
     */
    @Override
    public Result followCommons(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key="follows:" + userId;
        String key2="follows:" + id;
        //Set集合求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if(intersect==null||intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        //转成Long集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //查询用户信息
        List<User> users = userService.listByIds(ids);
        //转成user集合
        Stream<UserDTO> userDTO = users.stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class));

        return Result.ok(userDTO);
    }
}
